Practice club including pivotally mounted weight and latching member



March 9, 1965 M. v. BLAKE 3,172,663

PRACTICE CLUB INCLUDING PIVOTALLY MOUNTED WEIGHT A LAT NG MEMBER File eb. 1962 United States Patent 3,172,668 PRACTICE CLUB INfiLUDlNG PIVQTALLY MGUNTED WEEGHT AND LATCEEWG liiEh EBER Minden Vaughan Blaine, rCarnanton, Woodlands Road E, Virginia Water, Surrey, England Filed Feb. 12, 1962, Ser. No. 172,718 Claims priority, application Great Britain, Feb. 15, 61, 5,656 61 9 flaims. (6i. 273186) This invention relates to instructional and practice devices for teaching and maintaining the correct arm and body movements in ball games employing clubs, bats, rackets or the like, and has for its object to provide an improved device for enabling a player to practice swinging the club or the like.

While this invention may be applied to many sports, It may most readily be understood in its application to a golf stroke which will now be described. A good golf shot is made up of a steady acceleration of the club by the arms and body on the downward part of the stroke, followed by a rapid acceleration of the club by the wrists at the bottom of the stroke as the ball is hit, and culminating in a relaxed follow-through, the point of maximum angular velocity being ideally when the club head is in contact with the ball. To achieve efliciency, a considerable amount of practice has to be done. It is not desirable to practice by swinging a normal club without hitting anything as the mental impression is entirely different and there is no shock of impact to brace against. It is therefore desirable in a practice club to provide at the normal point of impact a resistance to the hands which gives the feel of hitting a bail,

According to this invention, a device for enabling a player to practice swinging a club, bat or the like cornprises a handle and mounting member carried on the handle, in which member a weight is pivotally mounted so that it is capable of being rotated about its pivot axis, means being provided for restricting the rotation of the weight about the pivot axis until it is released by centrifugal force, induced by the swing of the handle and mounting member, exceeding a predetermined value. This device will thus indicate the position in the swing when the club or the like attains a predetermined angular velocity. Preferably the device is arranged so that the release of the weight provides a resistance to the hands and o gives the feel of having hit a ball.

The mounting member conveniently is a casing for housing the weight and is preferably arranged so that the handle and easing closely simulate the appropriate type of club, bat or the like. For example, in the case of a golf practice device, the handle and easing may be arranged closely to simulate the handle and head of a golf club. In the above arrangement, as the handle and casing attain the required angular velocity, the weight may be released to swing outwardly and forwardly under centrifugal force so as to provide the aforementioned resistance to the hands thereby givin the feel of having hit a ball. Depending upon the position of the handle and casing on release of the weight the centrifugal force on the weight may be augmented or detracted from by gravitational force; in the case of a golf club when the striking position is at the lowest point of the swing, gravitational force will assist the centrifugal force giving outward movement of the weight. The motion of the Weight is conveniently stopped by impact with a stop comprising for example, a wall or projection on a wall of the casing at an instant when the centre of gravity of the head has moved forwardly and outwardly. This impact will give rise to a sound and an impulse which can be felt in the handle, thus giving two simultaneous indications of the 3,l72,tih8 Patented Mar. 9, 19b? time when the weight strikes the stop. Preferably the arrangement is such that the time of the sound and impulse is very shortly after the time of the release of the weight, so that effectively they will be experienced when the angular velocity required to release the weight is attained.

The weight may be mounted with its pivot axis substantially perpendicular to the line of swing of the required stroke so that the weight when released is moved outwardly and forwardly by the centrifugal force induced by the swing of the device. For a golf practice device where the maximum angular velocity should be obtained when the head of the club is in substantially the lowest point of the swing, that is to say the point where the ball would be struck if a normal club is being used to hit a ball, it is thus readily possible to arrange the weight and its pivot axis so that gravitational force as well will au ment the centrifugal force in effecting the rotational movement.

The centrifugal force on the weight may be used for effecting release of the weight. Preferably, however, the means for restricting the rotation of the weight comprises a latch member spring-urged into a position latching said weight, the latch member being arranged so that the centrifugal force on it due to a swing, when it exceeds a predetermined value, overcomes the spring force and moves the latch member to release the weight. The latch member may also be pivotally mounted and in this case may include a mass adjustable towards and away from the pivot axis of the latch member so that the angular velocity required to produce the necessary centrifugal force on the latch member to overcome the swing force may be adjusted by movement of the adjustable mass.

It is preferable that the axis of pivoting of the latch is substantially perpendicular to the line of swing of the required stroke. Since the angular velocity will be in creasing up to the time of release of the latch, it is preferable to take advantage of this and arrange the centre of gravity of the latch member in front of the latch pivot axis considered in the direction of movement during the swing. Most conveniently the weight swings in the opposite direction. Provided the weight moves outwardly, that is the radial distance from the centre of swing of the weight increases, when the weight is released, the player will get the impression of a ball being hit. The weight may be arranged to swing against a stop to give a sound simulating the impact of a club on a ball. The maximum impact against the stop is obtained by stopping the weight when the centre of gravity of the weight is at its maximum outward distance.

In many games, and particularly in golf it is desirable to know the direction of movement of the club relative to the striking face of the club at the moment of impact with the ball, or in other words to know whether the ball would be hooked or sliced. For this purpose there may be provided an element which sets itself in the direction of travel of the device and means for automatically clamping the element when the weight moves. Conveniently this indicator comprises a flexible member which will assume a position along the relative air stream, for example a piece of wool, attached at one end to a preferably fiat exterior surface of the casing containing the pivoted weight. The flexible member is attached in such a way that during the motion of a typical stroke it is free to be blown in the direction of the air stream over the particular surface of the casing. Clamp means may be employed to clamp the free end of the flexible member to the surface of the casing as the weight is released. The direction of the air stream relative to the surfaces of the casing on the inside or outside of the v t,

the moment the weight is released represents the amount by which the ball would have been hooked or sliced, and if the flexible member is attached to lie adjacent to one of those surfaces the position in which it is clamped conveys the required information. In the case of a golf club practice device, the flexible member is conveniently attached to the top surface of the casing, assuming the latter is at the bottom of the stroke.

The clamp means may take the form of a movable clamping member mounted parallel to the relevant surface of the casing and extending in a direction transverse to the line of typical stroke. The free end of the flexible member may pass between the clamping member and the casing and be clamped between the clamping member and the casing on the release of the weight.

It will be appreciated that the hooking or slicing indicator is not limited to the form specifically described, but may take one of many forms. For example, other devices which would be deflected in accordance with the air stream and clamped at the appropriate instant may be employed.

The device disclosed is useful in instruction and practice of many ball games employing clubs, bats or rackets or the like. It is particularly applicable to the game of golf. The mechanism described may conveniently be enclosed in a unit the size, shape and weight of the head of a golf club. Thus by attaching such a unit to the end of a suitable handle a practice club of the balance and feel of a true golf club is obtained.

The following is a description of one embodiment of the invention, reference being made to the accompanying drawings in which:

FIGURE 1 is a perspective view of the part of a golf practice device embodying the present invention;

FIGURE 2 is a vertical section through the device of FIGURE 1 in a plane normal to the face corresponding to the striking face of a golf club;

FIGURE 3 is an exploded view of part of the mechanism of the device of F IGURES 1 and 2;

FIGURE 4 is a perspective view of part of the mechanism of FIGURE 1 with part of the top casing cut away; and

FIGURES 5, 6 and 7 are explanatory diagrams illustrating the mechanism of FIGURES 1 to 4 in different positions during its operation.

The drawings illustrate a golf practice device for indieating the position in the swing of a golf club, more specifically a driver, when the club reaches a predetermined angular velocity. It is required that in driving a golf ball the maximum velocity should be reached at the bottom of the swing at the point where the club would be about to hit the ball. The device shown in the drawings gives a sound and a feel similar to that occurring when a ball is hit when the angular velocity reaches said predetermined value. This value can be adjusted and the player sets the adjustment to the velocity he is trying to reach and can then practice swinging so that he achieves the maximum velocity at the right point in the stroke.

The device is made to resemble as closely as possible a golf club and has a handle 10 of which only part of the lower end is shown and which would be made like a golf club handle. The lower part of the device as closely as possible simulates in size, shape and weight the head of a golf club and comprises a main body part 11 which may be formed of Wood attached to the handle 10 in the known manner. This head 11 has a hollow interior and, at what would be the striking face of the normal club, has a metal cover plate 12 which is secured in position by two bolts 13. The hollow interior is covered by a top cover plate 14 which may, like the plate 12, conveniently be a sheet metal plate. Along the two sides of the hollow interior, metal strips 15, 16 are secured by screws 17 so as to form supports for trunnions constituting pivots to be described later. These two metal strips 15, 16 are L- of the cavity, that is to say extending in the direction of swing of the club. At the forward ends of each of the members 15, 16 considered in the direction of swing, is a hole 13, these holes 18 forming the bearings for trunnions 19 on the two arms of a U-shaped member 20 which can thus swing about a pivot axis which is horizontal and normal to the line of swing. This member 20 constitutes the aforementioned weight and it is normally held in a latched position to be released by contrifugal force in a manner to be described later. The member 20 is shaped so that its centre of mass lies well behind the trunnions 19 and substantially in the same horizontal plane of the trunnion axis or only slightly below this plane when the Weight is latched and the club is in the position corresponding to the position of striking a ball as shown in FIGURE 2. The latch member for holding the weight 26 in this position is indicated generally at 21 in FIGURE 3 and is pivoted on trunnion arms 22 carried in bearings formed by holes 23 in the aforementioned plates 15, 16, these holes 23 being located rearwardly of the holes 18 considered in the direction of movement of the club during a stroke. The trunnion arms 22 are secured, for example, by brazing or Welding, to a metal tube 24- having an internal thread and into which extends a threaded rod 25 having a knurled head 26. The knurled head 26 is accessible from outside the body part 11 to permit of manual adjustment of the position of the rod 25 in the tube 24 so as thereby to alter the position of the centre of gravity of the latch member 21 with respect to the trunnion arms 22. The latch member is formed so that the centre of gravity is always slightly forward of these trunnion arms. Secured to the tube 24 is an arm which has a portion 27 extending generally at right angles to the tube and, beyond this, extends parallel to the tube 24 for a short distance to provide a concave surface 28 with its centre of curvature on the trunnion arm pivot axis. Beyond the end of the surface 28, the latch arm extends downwardly and forwardly to provide a concave cam surface 30 which is terminated at a T-shaped portion formed by outwardly extending arms 31. A rod 32 is secured to this arm on the underside thereof, the rod being curved to be approximately a circular are about the pivot axis of the trunnion arms 22. Around this rod 32 is arranged a helical spring 33 one end of which bears against a shoulder 34 on the latch member and the other end of which bears against the arms of a U-shaped plate 35 between which the rod 32 is movable. This U-shaped plate 35 has a flange 36 by means of which it is secured by screws 37 in the body 11 of the head of the club as most clearly seen in FIGURE 2. The U-shaped plate 35 could be made adjustable to alter the tension of the spring 33 and so give an additional range of adjustment of the angular velocity required for effecting release of the latch.

It will be seen that the spring 33 urges the lower end of the latch arm forwardly to the position shown in FIGURE 2. As the centre of gravity of the latch assembly is forward of the pivot axis defined by the trunnion arms 22, the centrifugal force on the latch assembly will tend to rotate this assembly about its pivot axis in a clockwise direction, as viewed in FIGURE 2, against the force of the spring. It will be immediately apparent that if the centre of gravity of the latch member was very close to its pivot axis, an extremely high angular velocity would be necessary to produce any appreciable force against the spring. As the said centre of gravity is moved further forward the necessary angular velocity required to produce any particular force will be reduced. The threaded rod 25 and tube 24 are arranged to enable the centre of mass to be adjusted over the required operating range so that the latch member will move back against the spring 33 at any angular velocity of swing such as might be required for practice purposes.

In the latching position, as shown in FIGURE 2, a roller 4%) on the bottom rearward edge of the pivoted weight 2% sits in the concave surface 28 on the latch member. In this position the assembly is quite rigid, the spring 33 pushing the front end of the latch arm against the plate 12 on the front edge of the club. Gravitational effects on the weight 26 cannot move that member since the force exerted through the roller 40 is at right angles to the surface 28 and the latch is arranged so that the member 20'is substantially at the upper limit of its travel. Conveniently in this position shoulders 41 on the member 20 bear against the underside of enlarged diameter portions 42 of the trunnion arms 22 thereby locking the member 20 against upward movement about its pivot axis. When the club is swung the centrifugal force initially can only be effective on the latch member 21 which can move about its pivot as soon as the centrifugal force on the latch member is sufiicient to overcome the pressure of the spring 33. The centrifugal force moves the latch member in the direction of the arrow A (FIGURE 5) to the position shown in that figure in which the aforementioned roller 40 can move off the surface 28 due to the angular displacement of the latch member. The member 20 has a recess in the central part of its upper surface, as most clearly seen in FIGURE 3, in order to permit of this movement of the latch member 21. The roller 4-0 rolls freely across the curved surface 28 on the latch arm as shown in FIGURE 5. As soon as it is clear of the end of this curved surface, it will move freely, under the action of centrifugal force and gravity on the member 20, along the curved surface 36 as shown in FIGURE 6, the member 24} moving in the direction of the arrow B. The member 26 continues to move until it strikes the aforementioned front plate 12. This will give a sound simulating the sound of a club striking a ball. The outward and forward movement of the member 2% (i.e. movement of the centre of mass'outwardly' and forwardly from the centre of swingof the device) as it travels from the'horizontal position of FIGURE 2 to the position shown in FIGURE 7 in which the centre of gravity of the member 20 is at a substantially greater distance outwardly from the centre of curvature of the motion of the club, and forward of the position shown in FIGURE 2, gives a retarding effect simulating impact resistance of the striking of a ball. The device is preferably arranged so that the resistance to the hands is equal to that felt when a normal club strikes a ball in a normal stroke.

In the initial position shown in FIGURE 2 the front end of the latch arm abuts against the plate 12, the spring 33 pushing the latch member to this position. Due to the angular movement of this arm under centrifugal force the front end moves rearwardly and with the particular construction illustrated, the striking surface on the member 26 which hits the plate 12 is so positioned that the roller 46 moves beyond the end of the cam surface 30 enabling the latch to move upwardly slightly behind the member 20 under the spring action so locking the mechanism in this condition. The arms 31 of the T are provided to limit this upward movement of the latch memher, the member 20 having shoulders which remain seated on these arms when the roller 49 moves off the end of the surface 3%). The slight upward movement of the latch member serves to retain the mechanism in this position until it is released which may readily be effected by a slight flick of the whole device in the reverse direction to the normal swing. The centrifugal force acting on the latch member moves that member down slightly and the deceleration at the end of the flick causes the member 26 to move rearwardly so that the roller moves back on to the surface 30 and rides up that surface. With the decreasing centrifugal force at the end of the flick the spring 33 pushes the latch upwardly so tending to force the roller 49 up the surface 3%. The roller 40 rides on to the curved surface 28 so that the device is re-set ready for use again.

In order to show the direction of travel of the head of the club at the moment when the. member 20 is released, there is provided a light streamer St), for ex.- ample a length of cotton thread or woollen thread having a fluffed out end 51. This thread is secured to a suitable support 52 near the front edge of the outer top surface 14; When the club is swung this thread 50 will stream backwards due to the air resistance on the fluffy head 51 and hence will set itself in the direction of movement of the club head. The thread 50 passes under abridge member 53 forming a clamp which exends across the top surface of the club head as shown in FIGURE 1 and which is carried on two supports 54 the lower ends of which have feet 55 (FIGURE 4) sit ting normally on the top surface of the member 20. Around'each of the legs 54 is a helical spring 56 which has one end bearing againsta foot 55 ancl'the other end bearing against the inner surface of the top cover plate 14; In the position shown in FIGURE 2 the member Zil forces the legs 54 and hence the bridge 53 upwardly so that there' is a clearance between the inside of the bridge 53 and the upper surface of the plate 14 through which the thread 50 can pass freely. As the club is swun this thread will take'up an angular position corresponding to the direction of movement of the club head through the air. As soon as the latch member is released and the weight 20 begins the drop as shown in FIGURE 5, the springs 56 press the feet 55 downwardly, so pulling the bridge member 53 downwardly to clamp the thread 59in the position in which it was at the time the latch member released. Thus by seeing the angular position of the line in which the thread Stltrails back from the support 52- when it is-clamped on the top plate 64, it can readily be seenwhether the club was swung correctly or whether it was swung in such a manner, if a ball was being struck, it would have been hooked or sliced. When the mechanism is re-set by a' rearward flick as described above, the bridge 53 is lifted by the resetting ofthe member 20 so that it is ready for the next swing.

I claim:

l. A device for enabling a player to practice swinging a club, bat or the like comprising a handle, a mounting member carried on the handle, a weight pivotally mounted in said member with its center of mass non-coincident with its pivot axis for rotation about said pivot axis when the device is swung by a user, a latch member pivotally mounted in said mounting member with its center of mass non-coincident with its pivot axis and means urging said latch member into a position restraining said weight against pivotal movement, said latch member being movably mounted in said mounting member for movement against the urging force under the action of centrifugal force when the device is swung to release said weight for rotational movement under the action of centrifugal force on the weight.

2. A device for enabling a player to practice swinging a club, hat or the like, comprising a handle, a mounting member carried on the handle, a weight pivotally mounted in said member with its center of mass non-coincident with its pivot axis for rotation about said pivot axis when the device is swung by a user, a latch member pivotally mounted in said mounting member and including a mass adjustable towards and away from the pivot axis of the latch member, and means urging said latch member into a position restraining said weight against pivotal movement, said latch member having its center of mass non-coincident with its pivot axis and arranged so that .it moves about its pivot axis against the urging force under the action of centrifugal force when the device is swung to release said weight for rotational movement under the action of centrifugal force on the weight.

3. A device as claimed in claim 2 adapted for normal swinging in one direction in one plane through the mounting member wherein the axis of pivoting of said weight is substantially perpendicular to the said plane of swing of the required stroke and the weight is arranged, when 7 V released, to move forwardly in the said direction of swing.

4. A device as claimed in claim 3 wherein the axis of pivoting of the latch member is substantially perpendicular to the said plane of swing of the required stroke.

5. A device as claimed in claim 3 and having a stop member positioned to stop forward movement of the weight when the center of gravity of the weigh at its maximum radial distance along the line of the handle.

6. A device for enabling a player to practice swinging a club, bat or the like adapted for normal swinging in one direction in one plane through the mounting member, comprising a handle, a mounting member carried on the handle, a weight pivotally mounted in said member with its center of mass non-coincident with its pivot axis for rotation about said pivot axis when the device is swung by a user, the axis of pivoting of said weight being substantially perpendicular to the said plane of swing of the required stroke and the weight arranged to move forwardly in the said direction of swing under centrifugal force when the device is swung, a latch member for restraining said weight against movement, said latch member being pivotally mounted in said mounting member with the axis of pivoting substantially perpendicular to the said plane of the required stroke and with the center of mass of the latch member non-coincident with its pivot axis, means urging said latch member into a position restraining said weight against pivotal movement, said latch member having its center of mass non-coincident with its pivot axis and arranged so that it moves about its pivot axis against the urging force under the action of centrifugal force when the device is swung to release said weight, and a stop member positioned to stop forward movement of the weight when the center of gravity of the weight is at its maximum radial distance along the line of the handle, said latch member and said weight having cooperatingsurfaces for the weight to ride over the latch member back to the latching position on flicking the device in the opposite direction to a normal swing.

7. A golf practice device for enabling a player to practice swinging a golf club, which device comprises a handle with a head at one end thereof extending transversely to the line ofthe handle to simulate a golf club adapted for normal swinging in one direction in one plane through the head, a weight pivotally mounted in said head with its center of mass non-coincident with its pivot axis for rotation about said pivot axis when the device is swung by a user, the axis of pivoting of said weight being substantially perpendicular to the said plane of swing of the required stroke and the weight arranged to move forwardly in the said direction of swing under centrifugal force when the device is swung, and latch means preventing rotation of said weight about said pivot axis, said latch means including a mass movable under centrifugal force and operative when the angular velocity exceeds a predetermined value to release said weight for rotational movement.

8. A golf practice device as claimed in claim 7 wherein, on said head, there is provided an element adapted to set itself in the said direction of travel of the head and means operated by said weight when released from the latched position to clamp said element when the weight is released.

9. A golf practice device as claimed in claim 7 where- V in a flexible member is attached to said head to trail over an exterior surface of said head, said flexible member extending freely over the surface to assume a position along the relative air stream when the device is swung and wherein clamp means are provided operated by said weight when the weight is released from its latched position to clamp said flexible element when the weight is released.

References Cited by the Examiner UNITED STATES PATENTS 2,501,277 3/50 Hollopeter 273l86 2,772,887 12/56 Blake 273186 3,113,781 12/63 Guier 273-186 DELBERT B. LOWE, Primary Examiner. 

1. A DEVICE FOR ENABLING A PLAYER TO PRACTICE SWINGING A CLUB, BAR OR THE LIKE COMPRISING A HANDLE, A MOUNTING MEMBER CARRIED ON THE HANDLE, A WEIGHT PIVOTALLY MOUNTED IN SAID MEMBER WITH ITS CENTER OF MASS NON-COINCIDENT WITH ITS PIVOT AXIS FOR ROTATION ABOUT SAID PIVOT AXIS WHEN THE DEVICE IS SWUNG BY A USER, A LATCH MEMBER PIVOTALLY MOUNTED IN SAID MOUNTING MEMBER WITH ITS CENTER OF MASS NON-COINCIDENT WITHITS PIVOT AXIS AND MEANS URGING SAID LATCH MEMBER INTO A POSITION RESTRAINING SAID WEIGHT AGAINST PIVOTAL MOVEMENT, SAID LATCH MEMBER BEING MOVABLY MOUNTED IN SAID MOUNTING MEMBER FOR MOVEMENT AGAINST THE URGING FORCE UNDER THE ACTION OF CENTRIFUGAL FORCE WHEN THE DEVICE IS SWUNG TO RELEASE SAID WEIGHT FOR ROTATIONAL MOVEMENT UNDER THE ACTION OF CENTRIFUGAL FORCE ON THE WEIGHT. 